Seasonal Variation in Sleep, Respiratory, and Cardiovascular Parameters Assessed by a Wearable Device
Open accessAbstract
Seasonal variation in sleep patterns is well recognized in PSG studies and actigraphy, yet few studies have comprehensively examined its impact on both sleep architecture and respiratory physiology using wearable technology. Circadian and environmental cues such as light exposure, temperature, and humidity may modulate sleep quality, apnea severity, and oxygenation, but large-scale, real-world data remain limited. We conducted a retrospective analysis of 2,386 home sleep studies, one study per individual, recorded between 2022 and 2025 using the SleepImage wearable system in Fresno, California. Each study was categorized by season of recording (winter, spring, summer, fall) based on start date. Key outcomes included total sleep duration, sleep latency, wake after sleep onset (WASO), mean and minimum SpO₂, apnea-hypopnea indices (sAHI3%, sAHI4%), respiratory disturbance indices (sRDI3%, sRDI4%), oxygen desaturation indices (ODI3%, ODI4%), and heart rate metrics. Analyses were adjusted for age using analysis of covariance (ANCOVA) and multiple linear regression to evaluate both main and interaction effects ( Season × Age ). Significant seasonal differences were observed in multiple parameters after adjusting for age. Sleep latency was longest in summer (836.97 ± 1007.76 sec) and shortest in fall (582.51 ± 661.49 sec, p < 0.001). Apnea hypopnea indices were highest in winter and lowest in fall ( p = 0.027), while mean SpO₂ and maximum SpO₂ were modestly reduced in colder months ( p < 0.001). Mean heart rate was higher in winter (68.3 ± 10.9 bpm) compared with summer (65.7 ± 9.3 bpm, p < 0.001). Interaction models revealed that age modified seasonal effects on sleep efficiency and latency, with older adults showing greater winter-related sleep latency increases but smaller seasonal fluctuations in apnea indices. Sleep and respiratory parameters exhibit distinct seasonal modulation, with winter months associated with higher apnea burden and reduced oxygenation, and summer associated with prolonged sleep latency and greater fragmentation.
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Written from the paper’s full text.
TL;DR
In 2,386 home sleep studies using the SleepImage wearable, winter was associated with higher apnea burden, lower oxygen saturation, and higher heart rate, while summer showed longer sleep latency and greater fragmentation. Seasonal patterns persisted after adjustment for age, sex, and sleep-disordered breathing severity, and longer daylight independently predicted longer sleep latency and greater WASO.
Key findings
- Sleep latency was longest in summer (13.95 ± 16.80 min) and shortest in fall (9.71 ± 11.02 min; p < 0.001); total sleep duration (p = 0.0006) and WASO (p = 0.0012) also varied significantly, with fall showing the longest sleep duration and summer the greatest fragmentation.
- AHI (4%) was highest in winter (15.42 ± 17.95 events/h) and lowest in fall (12.59 ± 15.87 events/h; p = 0.0269); mean SpO₂ was lower in winter and spring and higher in summer and fall (winter 93.85 ± 2.37%, summer 94.39 ± 2.08%; p = 0.0007).
- Mean heart rate was highest in winter (68.30 ± 10.86 bpm) and lowest in summer (65.73 ± 9.30 bpm; p < 0.001).
- Season × Age interactions were observed for sleep latency and sleep efficiency, with older adults showing greater winter-related sleep latency increases but smaller seasonal fluctuations in apnea indices; longer daylight was independently associated with longer sleep latency (β = 32.3 sec per hour, p = 0.003) and greater WASO (β = 59.0 sec per hour, p = 0.004), but not total sleep duration.
Methods
- Retrospective cross-sectional analysis of 2,386 consecutive home sleep studies, one per adult patient, recorded between June 2022 and October 2025 in Fresno, California, using the FDA-cleared SleepImage Ring system (version 2.2.0).
- Mean participant age was 52.4 ± 14.2 years and 49.1% were women; studies were categorized by season: winter (n = 463), spring (n = 472), summer (n = 640), and fall (n = 811).
- Seasonal differences were assessed with ANCOVA adjusted for age, followed by multivariable linear regression including season, age, sex, and SDB severity (AHI); Tukey post hoc tests were used for significant season effects, and Season × Age interactions and photoperiod as a continuous predictor were also modeled.
Limitations
- The authors state that wearable systems allow large-scale, ecologically valid data but lack some detailed physiological measurements available in in-laboratory polysomnography; environmental variables such as ambient temperature, humidity, and photoperiod were not directly measured.
- The authors state that BMI, comorbidities, medication use, and lifestyle factors such as physical activity, caffeine intake, and alcohol consumption were unavailable; seasonal categorization based on meteorological definitions may introduce artificial boundaries, and each participant contributed a single sleep study, so differences reflect between-subject comparisons rather than within-individual seasonal change.
- The authors note that residual confounding cannot be excluded despite adjustment for age, sex, and SDB severity, and that longitudinal repeated-measures studies are needed to confirm whether seasonal patterns persist within individuals over time.
Model-written summary. Check it against the paper before relying on it.
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Cites
Statistics
Claims the paper makes
9 of 26 cited sources checked · 4 supported · 0 flagged · accuracy not yet measured
- Premisecitation
Even short-term exposure to natural light (e.g., a weekend of camping) was sufficient to induce substantial shifts in circadian phase, indicating that the human circadian clock retains sensitivity to seasonal photic cues in modern environments.
“Importantly, even short-term exposure to natural light (e.g., a weekend of camping) was sufficient to induce substantial shifts in circadian phase, indicating that the human circadian clock retains sensitivity to seasonal photic cues in modern environments.”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites Stothard et al., 2017 source
- Interpretationcitation
Our results are consistent with prior actigraphy and polysomnographic studies reporting longer total sleep time and altered sleep architecture during winter months.
“Our results are consistent with prior actigraphy, and polysomnographic studies reported longer total sleep time and altered sleep architecture during winter months (Seidler et al., 2023).”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites Seidler et al., 2023 source
The Abstract reports polysomnographic findings in patients with sleep disturbances: total sleep time was longer in winter than summer, though that difference was not statistically significant, and REM sleep was longer in winter than spring. The Results also report significantly longer winter than spring total sleep time. The paper supports the sleep-architecture finding, but it is not an actigraphy study, and the claim omits the limits on the total-sleep-time finding. (LLM, conf=0.88)
Experimental — accuracy not yet measured
- Premisecitation
The human circadian system remains responsive to seasonal variation in the natural light-dark cycle despite widespread exposure to artificial lighting.
“Recent experimental work demonstrates that the human circadian system remains responsive to seasonal variation in the natural light-dark cycle despite widespread exposure to artificial lighting.”
Quote in the paperSubstantial claim1 of 1 sources checked- cites Stothard et al., 2017 source
- Findingown data
REM duration exhibited significant seasonal differences.
“REM duration and wake transitions exhibited smaller but significant seasonal differences (Table 1).”
Quote in the paperNot a substantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Maximum heart rate followed similar seasonal patterns.
“Minimum and maximum heart rate followed similar patterns.”
Quote in the paperNot a substantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Maximum respiratory event duration varied seasonally, with slightly longer events in winter.
“Mean and maximum respiratory event duration also varied seasonally, with slightly longer events in winter.”
Quote in the paperNot a substantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Heart rate metrics showed robust seasonal differences.
“Heart rate metrics showed robust seasonal differences.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Significant Season × Age interactions were observed for sleep latency and sleep efficiency.
“Significant Season × Age interactions were observed for sleep latency and sleep efficiency.”
Quote in the paperNot a substantial claim - Findingown data
Obstructive respiratory indices demonstrated consistent seasonal variation after age adjustment.
“Obstructive respiratory indices demonstrated consistent seasonal variation after age adjustment.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
No significant Season × Age interaction was observed for oxygenation parameters.
“No significant Season × Age interaction was observed for oxygenation parameters.”
Quote in the paperNot a substantial claim - Findingown data
Longer daylight duration was independently associated with longer sleep latency (β = 32.3 sec per hour, p = 0.003).
“When photoperiod (hours of daylight in Fresno, California) was modeled as a continuous predictor adjusting for age, longer daylight duration was independently associated with longer sleep latency (β = 32.3sec per hour, p = 0.003) and greater WASO (β = 59.0 sec per hour, p = 0.004), but not with total sleep duration.”
Quote in the paperSubstantial claim- Rests on an assumption: Photoperiod (hours of daylight in Fresno, California) is a valid proxy for individual environmental light exposure relevant to sleep.
- Findingown data
Male sex was independently associated with lower mean heart rate.
“Male sex was independently associated with lower mean heart rate; however, seasonal effects remained stable after adjustment.”
Quote in the paperNot a substantial claim - Findingown data
SDB severity was independently associated with increased WASO.
“SDB severity was independently associated with increased WASO and modestly shorter sleep duration but was not independently associated with sleep latency.”
Quote in the paperNot a substantial claim - Findingown data
Male sex did not diminish the seasonal effect on respiratory indices.
“Male sex was independently associated with higher REM apnea index and longer event duration but did not diminish the seasonal effect.”
Quote in the paperNot a substantial claim - Findingown data
SDB severity was not independently associated with sleep latency.
“SDB severity was independently associated with increased WASO and modestly shorter sleep duration but was not independently associated with sleep latency.”
Quote in the paperNot a substantial claim - Findingown data
Summer demonstrated the greatest sleep fragmentation (WASO).
“Total sleep duration (p = 0.0006) and WASO (p = 0.0012) also varied significantly, with fall showing the longest sleep duration and summer demonstrating the greatest fragmentation.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
After adjusting for age, multiple sleep and respiratory parameters demonstrated significant seasonal variation (p < 0.05).
“After adjusting for age (ANCOVA), multiple sleep and respiratory parameters demonstrated significant seasonal variation (p < 0.05).”
- Also stated in: § Abstract · plain
“Significant seasonal differences were observed in multiple parameters after adjusting for age.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Also stated in: § Abstract · plain
- Findingown data
SDB severity was independently associated with modestly shorter sleep duration.
“SDB severity was independently associated with increased WASO and modestly shorter sleep duration but was not independently associated with sleep latency.”
Quote in the paperNot a substantial claim - Findingown data
Total sleep duration varied significantly across seasons after age adjustment (p = 0.0006).
“Total sleep duration (p = 0.0006) and WASO (p = 0.0012) also varied significantly, with fall showing the longest sleep duration and summer demonstrating the greatest fragmentation.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Wake transitions exhibited significant seasonal differences.
“REM duration and wake transitions exhibited smaller but significant seasonal differences (Table 1).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Male sex was independently associated with longer event duration.
“Male sex was independently associated with higher REM apnea index and longer event duration but did not diminish the seasonal effect.”
Quote in the paperNot a substantial claim - Findingown data
Male sex was independently associated with higher REM apnea index.
“Male sex was independently associated with higher REM apnea index and longer event duration but did not diminish the seasonal effect.”
Quote in the paperNot a substantial claim - Findingown data
CVHR-derived instability measures varied modestly by season.
“Cyclic Variations in Heart Rate (CVHR)-derived instability measures also varied modestly by season.”
Quote in the paperNot a substantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Longer daylight duration was independently associated with greater WASO (β = 59.0 sec per hour, p = 0.004).
“When photoperiod (hours of daylight in Fresno, California) was modeled as a continuous predictor adjusting for age, longer daylight duration was independently associated with longer sleep latency (β = 32.3sec per hour, p = 0.003) and greater WASO (β = 59.0 sec per hour, p = 0.004), but not with total sleep duration.”
Quote in the paperSubstantial claim- Rests on an assumption: Photoperiod (hours of daylight in Fresno, California) is a valid proxy for individual environmental light exposure relevant to sleep.
- Findingown data
Fall showed the longest total sleep duration among seasons.
“Total sleep duration (p = 0.0006) and WASO (p = 0.0012) also varied significantly, with fall showing the longest sleep duration and summer demonstrating the greatest fragmentation.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Minimum heart rate followed similar seasonal patterns.
“Minimum and maximum heart rate followed similar patterns.”
Quote in the paperNot a substantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Indices reflecting apnea stability and REM-related apnea burden showed significant seasonal variation (all p < 0.01).
“Indices reflecting apnea stability and REM-related apnea burden showed significant seasonal variation (all p < 0.01).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
WASO varied significantly across seasons after age adjustment (p = 0.0012).
“Total sleep duration (p = 0.0006) and WASO (p = 0.0012) also varied significantly, with fall showing the longest sleep duration and summer demonstrating the greatest fragmentation.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Mean respiratory event duration varied seasonally, with slightly longer events in winter.
“Mean and maximum respiratory event duration also varied seasonally, with slightly longer events in winter.”
Quote in the paperNot a substantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Findingown data
Longer daylight duration was not associated with total sleep duration.
“When photoperiod (hours of daylight in Fresno, California) was modeled as a continuous predictor adjusting for age, longer daylight duration was independently associated with longer sleep latency (β = 32.3sec per hour, p = 0.003) and greater WASO (β = 59.0 sec per hour, p = 0.004), but not with total sleep duration.”
Quote in the paperSubstantial claim- Rests on an assumption: Photoperiod (hours of daylight in Fresno, California) is a valid proxy for individual environmental light exposure relevant to sleep.
- Study design and conductown data
In models including sex, seasonal effects on sleep architecture remained materially unchanged.
“In models including sex, seasonal effects remained materially unchanged.”
Quote in the paperNot a substantial claim - Study design and conductown data
In multivariable models including sex, seasonal associations for respiratory indices persisted.
“In multivariable models including sex, seasonal associations persisted.”
Quote in the paperSubstantial claim - Study design and conductown data
Combined age-and sex-adjusted models demonstrated stable seasonal coefficients across respiratory outcomes.
“Combined age-and sex-adjusted models demonstrated stable seasonal coefficients across respiratory outcomes.”
Quote in the paperSubstantial claim - Study design and conductown data
Adjustment for SDB severity did not eliminate seasonal effects on sleep latency, total sleep duration, or WASO.
“Adjustment for SDB severity did not eliminate seasonal effects on sleep latency, total sleep duration, or WASO.”
Quote in the paperSubstantial claim - Study design and conductown data
Adjustment for sex and SDB severity did not eliminate seasonal differences in mean oxygen saturation.
“Adjustment for sex and SDB severity did not eliminate seasonal differences in mean oxygen saturation.”
Quote in the paperSubstantial claim - Study design and conductown data
Seasonal effects on heart rate remained stable after adjustment.
“Male sex was independently associated with lower mean heart rate; however, seasonal effects remained stable after adjustment.”
Quote in the paperSubstantial claim - Study design and conductown data
No meaningful attenuation was observed in fully adjusted models for heart rate.
“No meaningful attenuation was observed in fully adjusted models.”
Quote in the paperSubstantial claim - Premisecitation
Kristal-Boneh et al. (2000) found HRV indices were lower in summer than winter.
“In a related analysis of 24-h HRV, Kristal-Boneh et al. (2000) found HRV indices were lower in summer than winter.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Kristal-Boneh et al., 2000 source
- Interpretationown data
These findings support a graded environmental effect on sleep initiation and fragmentation beyond categorical seasonal grouping.
“These findings support a graded environmental effect on sleep initiation and fragmentation beyond categorical seasonal grouping.”
Quote in the paperSubstantial claim- Rests on an assumption: Photoperiod (hours of daylight in Fresno, California) is a valid proxy for individual environmental light exposure relevant to sleep.
- Interpretationcitation
Our findings in heart rate are supported by ambulatory adult studies demonstrating higher cardiovascular strain in colder months.
“Our findings in heart rate are also supported by ambulatory adult studies demonstrating higher cardiovascular strain in colder months.”
Quote in the paperNot a substantial claim - Interpretationown data
This supports the hypothesis that seasonal variation in sleep architecture may be partly mediated by environmental light exposure rather than categorical seasonal grouping alone.
“This supports the hypothesis that seasonal variation in sleep architecture may be partly mediated by environmental light exposure rather than categorical seasonal grouping alone.”
Quote in the paperSubstantial claim- Rests on an assumption: Photoperiod (hours of daylight in Fresno, California) is a valid proxy for individual environmental light exposure relevant to sleep.
- Interpretationcitation
Our study results are consistent with both pediatric and adult polysomnographic studies showing a higher apnea burden during colder months.
“In terms of breathing physiology, our study results are consistent with both pediatric and adult polysomnographic studies showing a higher apnea burden during colder months.”
Quote in the paperSubstantial claim - Interpretationreasoning
The findings support a multifactorial model of seasonal sleep modulation in which environmental temperature, behavioral adaptation, and circadian-autonomic interactions contribute alongside photoperiod.
“The findings, therefore, support a multifactorial model of seasonal sleep modulation in which environmental temperature, behavioral adaptation, and circadian-autonomic interactions contribute alongside photoperiod.”
Quote in the paperSubstantial claim - Premisecitation
Even in the modern era of artificial light, the interplay between circadian and seasonal timing remains biologically meaningful.
“These findings highlight that, even in the modern era of artificial light, the interplay between circadian and seasonal timing remains biologically meaningful (Onishi et al., 2020).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites Onishi et al., 2020 source
- Study design and conductown data
In sensitivity analyses including calendar year as a fixed effect, seasonal coefficients across sleep architecture, respiratory, and autonomic outcomes remained directionally consistent and materially unchanged in magnitude.
“In sensitivity analyses including calendar year as a fixed effect, seasonal coefficients across sleep architecture, respiratory, and autonomic outcomes remained directionally consistent and materially unchanged in magnitude.”
Quote in the paperSubstantial claim - Premisecitation
Participants interviewed in summer reported slightly shorter sleep duration than those in winter (6.76 vs 6.84 h).
“Overall, participants interviewed in summer reported slightly shorter sleep duration than those in winter (6.76 vs 6.84 h) (Zolfaghari et al., 2023).”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Zolfaghari et al., 2023 source
- Study design and conductreasoning
Because each participant contributed a single sleep study, the observed seasonal differences reflect between-subject comparisons rather than within-individual seasonal change.
“Because each participant contributed a single sleep study, the observed seasonal differences reflect between-subject comparisons rather than within-individual seasonal change.”
Quote in the paperSubstantial claim - Premisecitation
Walter et al. showed that in a cohort of 257 children undergoing polysomnography, the OAHI demonstrated significantly higher severity during winter and spring compared with autumn and summer.
“Walter et al. in a cohort of 257 children undergoing polysomnography showed that the OAHI demonstrated significantly higher severity during winter and spring compared with autumn and summer (Walter et al., 2013).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites Walter et al., 2013 source
- Premisecitation
There is evidence using actigraphy in healthy populations that reported longer total sleep time during winter and shorter sleep during summer months.
“There is evidence using actigraphy in healthy populations that reported longer total sleep time during winter and shorter sleep during summer months (Jouvencel et al., 2025).”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Jouvencel et al., 2025 source
- May combine two claims. 37
- Classified as probably not a substantial claim. 15
May combine two claims.
PremisecitationFigueiro and Rea demonstrated that adolescents obtained significantly less sleep during the spring compared with winter, attributing this difference to increased evening daylight delaying circadian phase and bedtime, without a compensatory delay in school start times.
“Figueiro and Rea demonstrated that adolescents obtained significantly less sleep during the spring compared with winter, attributing this difference to increased evening daylight delaying circadian phase and bedtime, without a compensatory delay in school start times (Figueiro and Rea, 2010;Seidler et al., 2023;Karunanayake et al., 2021).”
Quote in the paperNot a substantial claim2 of 3 sources checked- cites Figueiro and Rea, 2010
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- cites Seidler et al., 2023 source
Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
Experimental — accuracy not yet measured - cites Karunanayake et al., 2021 source
Split into 2 atoms — 0 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 1 unverifiable. Expand the claim to see per-atom verdicts.
Experimental — accuracy not yet measured
May combine two claims.
PremisecitationColder ambient conditions increase sympathetic activation and peripheral vasoconstriction, and winter months are associated with higher rates of respiratory infections, reduced physical activity, and modest weight gain, each of which can contribute to higher nocturnal heart rate.
“Physiologically, colder ambient conditions increase sympathetic activation and peripheral vasoconstriction, and winter months are also associated with higher rates of respiratory infections, reduced physical activity, and (in many populations) modest weight gain, each of which can contribute to higher nocturnal heart rate (Bhutani et al., 2020).”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites Bhutani et al., 2020 source
Split into 2 atoms — 0 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 1 unverifiable. Expand the claim to see per-atom verdicts.
Experimental — accuracy not yet measured
May combine two claims.
PremisecitationStothard et al. (2017) showed that the timing and duration of the biological night shift in response to seasonal photoperiod, with an expansion of biological night during winter and earlier circadian timing following exposure to natural light conditions.
“Stothard et al. (2017) showed that the timing and duration of the biological night shift in response to seasonal photoperiod, with an expansion of biological night during winter and earlier circadian timing following exposure to natural light conditions.”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites Stothard et al., 2017 source
May combine two claims.
PremisecitationKarunanayake and colleagues observed clear seasonal shifts in sleep patterns, with shorter sleep duration, later bedtimes, and poorer self-reported sleep quality during longer photoperiod months.
“In a community-based study of two First Nation populations in Saskatchewan, Karunanayake and colleagues observed clear seasonal shifts in sleep patterns, with shorter sleep duration, later bedtimes, and poorer self-reported sleep quality during longer photoperiod months, highlighting the influence of natural light exposure in real-world settings.”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites Karunanayake et al., 2021 source
The Discussion reports shorter sleep during May–August than during fall and winter. But the Results report no significant seasonal difference in usual bedtime or overall sleep-problem measures; they do not establish poorer self-reported sleep quality during longer-photoperiod months. The paper also does not establish natural light exposure as the cause of the observed changes. (LLM, conf=0.90)
Experimental — accuracy not yet measured
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationPolysomnographic studies also described seasonal differences in sleep architecture, including changes in REM sleep duration, especially in clinical populations.
“Polysomnographic studies also described seasonal differences in sleep architecture, including changes in rapid eye movement (REM) sleep duration, especially in clinical populations (Seidler et al., 2023).”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites Seidler et al., 2023 source
May combine two claims.
Findingown dataMean SpO2 was lower in winter and spring and higher in summer and fall, with significant seasonal variation (p = 0.0007).
“Mean and maximum SpO₂ demonstrated modest but significant seasonal variation (p = 0.0007 and p = 0.0003, respectively), with lower values in winter and spring and higher values in summer and fall.”
- Also stated in: § Abstract · plain
“mean SpO₂ and maximum SpO₂ were modestly reduced in colder months (p < 0.001).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Also stated in: § Abstract · plain
May combine two claims.
Findingown dataThe study included 2,386 home sleep studies, one per individual, recorded between 2022 and 2025 using the SleepImage wearable system in Fresno, California.
“We conducted a retrospective analysis of 2,386 home sleep studies, one study per individual, recorded between 2022 and 2025 using the SleepImage wearable system in Fresno, California.”
- Also stated in: § METHODS · plain
“After excluding studies with incomplete demographic or signal data, 2386 were included in the analysis.”
Quote in the paperSubstantial claim- Also stated in: § METHODS · plain
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Findingown dataThe seasonal distribution of studies was winter n = 463, spring n = 472, summer n = 640, and fall n = 811.
“Each study was categorized by the date of acquisition into 4 seasons: winter (n = 463), spring (n = 472), summer (n = 640), and fall (n = 811).”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataREM apnea index was lowest in summer and highest in fall and winter.
“REM apnea index was lowest in summer and highest in fall and winter.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
May combine two claims.
Findingown dataMean heart rate was highest in winter (68.30 ± 10.86 bpm) and lowest in summer (65.73 ± 9.30 bpm; p < 0.001).
“Mean heart rate was higher in winter (68.3 ± 10.9 bpm) compared with summer (65.7 ± 9.3 bpm, p < 0.001).”
- Also stated in: § Autonomic Parameters · plain
“Mean heart rate was highest in winter (68.30 ± 10.86 bpm) and lowest in summer (65.73 ± 9.30 bpm; p < 0.001).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Also stated in: § Autonomic Parameters · plain
May combine two claims.
Findingown dataMaximum SpO2 was lower in winter and spring and higher in summer and fall, with significant seasonal variation (p = 0.0003).
“Mean and maximum SpO₂ demonstrated modest but significant seasonal variation (p = 0.0007 and p = 0.0003, respectively), with lower values in winter and spring and higher values in summer and fall.”
- Also stated in: § Abstract · plain
“mean SpO₂ and maximum SpO₂ were modestly reduced in colder months (p < 0.001).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Also stated in: § Abstract · plain
May combine two claims.
Findingown dataSleep latency differed significantly across seasons after age adjustment, longest in summer and shortest in fall.
“Sleep latency was longest in summer (836.97 ± 1007.76 sec) and shortest in fall (582.51± 661.49sec, p < 0.001).”
- Also stated in: § Sleep Architecture · plain
“After adjustment for age, sleep latency differed significantly across seasons, F(3, 2376) = 9.69, p < 0.001, longest in summer (13.95 ± 16.80 min) and shortest in fall (9.71 ± 11.02 min).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Also stated in: § Sleep Architecture · plain
May combine two claims.
Findingown dataMinimum SpO2 followed a similar pattern but did not reach statistical significance.
“Minimum SpO₂ followed a similar pattern but did not reach statistical significance.”
Quote in the paperNot a substantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
May combine two claims.
Findingown dataMale sex was independently associated with shorter sleep latency but did not attenuate seasonal differences.
“Male sex was independently associated with shorter sleep latency but did not attenuate seasonal differences (Supplementary Table S1).”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataAHI (4% criterion) was highest in winter and lowest in fall after age adjustment.
“Apnea hypopnea indices were highest in winter and lowest in fall (p = 0.027)”
- Also stated in: § Respiratory Indices · plain
“The AHI (4% criterion) was highest in winter (15.42 ± 17.95 events/h) and lowest in fall (12.59± 15.87 events/h; p = 0.0269).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
- Also stated in: § Respiratory Indices · plain
May combine two claims.
Findingown dataA significant Season × Age interaction was observed for AHI (4%), such that the age-related increase in AHI was modestly attenuated in winter relative to fall.
“A significant Season × Age interaction was observed for AHI (4%), such that the age-related increase in AHI was modestly attenuated in winter relative to fall.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Findingown dataThe mean participant age was 52.4 ± 14.2 years and 49.1% were women.
“The mean participant age was 52.4 ± 14.2 years and 49.1% were women.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataSimilar seasonal patterns were observed for AHI (3%), obstructive AHI (3% and 4%), and respiratory disturbance indices, with higher values in winter and fall and lower values in spring and summer.
“Similar patterns were observed for AHI (3%), obstructive AHI (3% and 4%), and respiratory disturbance indices, with higher values in winter and fall and lower values in spring and summer (Table 1).”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
May combine two claims.
Findingown dataAcross domains, winter was characterized by higher obstructive AHI, higher mean heart rate, and lower oxygen saturation, whereas summer was associated with longer sleep latency and greater sleep fragmentation.
“Across domains, winter was characterized by higher obstructive AHI, higher mean heart rate, and lower oxygen saturation, whereas summer was associated with longer sleep latency and greater sleep fragmentation.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
May combine two claims.
Findingown dataModeling photoperiod as a continuous variable demonstrated that longer daylight duration independently predicted longer sleep latency and increased WASO.
“Modeling photoperiod as a continuous variable further demonstrated that longer daylight duration independently predicted longer sleep latency and increased WASO.”
Quote in the paperSubstantial claim- Rests on an assumption: Photoperiod (hours of daylight in Fresno, California) is a valid proxy for individual environmental light exposure relevant to sleep.
May combine two claims.
Study design and conductown dataThese associations remained significant after adjustment for sex and were not materially altered in fully adjusted models.
“These associations remained significant after adjustment for sex and were not materially altered in fully adjusted models.”
Quote in the paperSubstantial claimMay combine two claims.
Study design and conductown dataFully adjusted models including age and sex showed stable effect sizes, confirming that seasonal variation in sleep architecture was not explained by demographic composition.
“Fully adjusted models including age and sex showed stable effect sizes, confirming that seasonal variation in sleep architecture was not explained by demographic composition.”
Quote in the paperSubstantial claimMay combine two claims.
PremisecitationHuman sleep and breathing physiology are deeply influenced by internal circadian systems and external seasonal cues.
“Human sleep and breathing physiology are deeply influenced by internal circadian systems and external seasonal cues (Stephenson, 2007;Baranwal et al., 2023).”
Quote in the paperSubstantial claim0 of 2 sources checkedMay combine two claims.
Interpretationown dataThese seasonal patterns persisted after adjustment for age, sex, and SDB severity, indicating independent seasonal modulation of sleep and respiratory physiology.
“These seasonal patterns persisted after adjustment for age, sex, and SDB severity, indicating independent seasonal modulation of sleep and respiratory physiology.”
Quote in the paperSubstantial claimMay combine two claims.
Study design and conductown dataAdjustment for year did not attenuate the observed winter elevation in AHI or heart rate, nor the summer increase in sleep latency and WASO, indicating that the seasonal patterns were stable across the 4-year study period.
“Adjustment for year did not attenuate the observed winter elevation in AHI or heart rate, nor the summer increase in sleep latency and WASO, indicating that the seasonal patterns were stable across the 4-year study period (Supplementary Table S2).”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationown dataIn conclusion, this study provides evidence that sleep architecture, oxygenation, and respiratory indices vary systematically across seasons, even in regions without a strong photoperiod change.
“In conclusion, this study provides evidence that sleep architecture, oxygenation, and respiratory indices vary systematically across seasons, even in regions without a strong photoperiod change.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
May combine two claims.
InterpretationcitationOur findings align with prior population-based studies and provide converging evidence that sleep duration and sleep-related symptoms vary systematically across seasons, largely driven by changes in daylight exposure.
“Our findings align with prior population-based studies and provide converging evidence that sleep duration and sleep-related symptoms vary systematically across seasons, largely driven by changes in daylight exposure.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim.
PremisecitationWescott et al. (2024) demonstrated that the association between light sensitivity and circadian phase differs by season.
“More recently, Wescott et al. (2024) demonstrated that the association between light sensitivityindexed via melanopsin-mediated intrinsically photosensitive retinal ganglion cell responsivity-and circadian phase differs by season.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites Wescott et al., 2024 source
Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).
Study design and conductnone givenSeasonal categorization based on meteorological definitions may introduce artificial boundaries, as physiologic transitions likely occur gradually rather than abruptly.
“Seasonal categorization based on meteorological definitions may also introduce artificial boundaries, as physiologic transitions likely occur gradually rather than abruptly.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenEnvironmental variables such as ambient temperature, humidity, and photoperiod were not directly measured.
“In addition, environmental variables such as ambient temperature, humidity, and photoperiod were not directly measured.”
Quote in the paperNot a substantial claimMay combine two claims.
PremisecitationThe central circadian pacemaker synchronizes with the 24-h day via light-dark cycles, but longer-term photoperiod shifts across seasons (circannual rhythms) also modulate physiological systems.
“The central circadian pacemaker synchronizes with the 24-h day via light-dark cycles, but longerterm photoperiod shifts across seasons (circannual rhythms) also modulate physiological systems (Swaab et al., 1996;Onishi et al., 2020).”
Quote in the paperSubstantial claim0 of 2 sources checkedProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductreasoningAlthough the study adjusted for age, sex, and SDB severity, residual confounding cannot be excluded.
“Although we adjusted for age, sex, and SDB severity, residual confounding cannot be excluded.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
InterpretationreasoningThe observation of seasonal variation in Fresno, California, a region with relatively mild photoperiod variation, is particularly notable.
“The observation of seasonal variation in Fresno, California, a region with relatively mild photoperiod variation, is particularly notable.”
Quote in the paperSubstantial claim- Rests on an assumption: Fresno, California has relatively mild photoperiod variation.
May combine two claims.
InterpretationcitationSeasonal modulation affects not only light exposure but also the physiological responsiveness of the circadian system itself.
“Seasonal modulation then affects not only light exposure but also the physiological responsiveness of the circadian system itself.”
Quote in the paperSubstantial claimMay combine two claims.
PremisecitationCassol et al. studied a PSG dataset (7523 adults across 10 years) analyzed with cosinor methods and showed a circannual pattern in AHI with a winter peak and summer nadir; AHI was higher during colder months even after adjusting for sex, age, BMI, neck circumference, and humidity.
“In adults, Cassol et al. studied a polysomnography (PSG) dataset (7523 adults across 10 years) analyzed with cosinor methods showed a circannual pattern in AHI with a winter peak and summer nadir; AHI was higher during colder months even after adjusting for sex, age, body mass index (BMI), neck circumference, and humidity (Cassol et al., 2012).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites Cassol et al., 2012 source
May combine two claims.
Interpretationown dataDespite limitations, the large sample size and consistent seasonal trends across multiple sleep and respiratory parameters, persisting after demographic adjustment, strengthen the validity of the findings.
“Despite these limitations, the large sample size and consistent seasonal trends across multiple sleep and respiratory parameters, persisting after demographic adjustment strengthens the validity of our findings.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim. May combine two claims.
PremisecitationGreater photic sensitivity was associated with later circadian phase during summer but not winter, suggesting that the strength of circadian photoentrainment varies as a function of seasonal context.
“Specifically, greater photic sensitivity was associated with later circadian phase during summer but not winter, suggesting that the strength of circadian photoentrainment varies as a function of seasonal context (Wescott et al., 2024).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites Wescott et al., 2024 source
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationZolfaghari and colleagues reported that sleep complaints, including insomnia symptoms and daytime sleepiness, varied by season, with additional perturbations around daylight saving time transitions.
“Extending these findings to older adults, Zolfaghari and colleagues analyzed longitudinal data from the Canadian Longitudinal Study on Aging and reported that sleep complaints, including insomnia symptoms and daytime sleepiness, varied by season, with additional perturbations observed around daylight saving time transitions”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Zolfaghari et al., 2023 source
May combine two claims.
PremisecitationHumans living at high latitudes display seasonal variation in melatonin rhythms, sleep timing, body temperature, and hormonal secretion.
“For example, research has shown that humans living at high latitudes display seasonal variation in melatonin rhythms, sleep timing, body temperature, and hormonal secretion (Honma et al., 1992).”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Honma et al., 1992 source
May combine two claims.
PremisecitationKristal-Boneh et al. reported seasonal change in 24-h blood pressure and heart rate, with evidence of increased cardiovascular load in winter.
“Kristal-Boneh et al. reported seasonal change in 24-h blood pressure and heart rate, with evidence of increased cardiovascular load in winter (Kristal-Boneh et al., 1997).”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Kristal-Boneh et al., 1997 source
Probably not a substantial claim: may not pass S2 (checkable).
Interpretationown dataThese findings emphasize the important interaction between environmental rhythms and biological regulation of sleep and breathing.
“These findings emphasize the important interaction between environmental rhythms and biological regulation of sleep and breathing.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationown dataAfter adjustment for age, sex, and SDB severity, winter was characterized by higher apnea hypopnea indices, lower oxygen saturation, and elevated nocturnal heart rate, whereas summer showed longer sleep latency and greater sleep fragmentation.
“After adjustment for age, sex, and SDB severity, winter was characterized by higher apnea hypopnea indices, lower oxygen saturation, and elevated nocturnal heart rate, whereas summer showed longer sleep latency and greater sleep fragmentation.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
May combine two claims.
Interpretationown dataThe study demonstrates clear seasonal modulation of sleep architecture, respiratory burden, oxygenation, and autonomic parameters in a large cohort of 2386 home sleep studies.
“Our study demonstrates clear seasonal modulation of sleep architecture, respiratory burden, oxygenation, and autonomic parameters in a large cohort of 2386 home sleep studies conducted using a wearable monitoring system between 2022 and 2025.”
Quote in the paperSubstantial claim- Rests on an assumption: The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
Probably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenLifestyle factors such as physical activity, caffeine intake, and alcohol consumption were unavailable.
“Lifestyle factors such as physical activity, caffeine intake, and alcohol consumption were also unavailable.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim. May combine two claims.
Study design and conductnone givenWearable systems allow for large-scale, ecologically valid data collection, but they lack some of the detailed physiological measurements available in in-laboratory polysomnography.
“Wearable systems allow for large-scale, ecologically valid data collection, but they lack some of the detailed physiological measurements available in in-laboratory polysomnography.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenDemographic and clinical covariates, including BMI, comorbidities, and medication use, were not included in the current models.
“Demographic and clinical covariates, including BMI, comorbidities, and medication use, were not included in the current models.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
PremisecitationIn-laboratory studies have reported a higher apnea-hypopnea index (AHI) during winter compared with summer.
“In-laboratory studies have reported a higher apnea-hypopnea index (AHI) during winter compared with summer (Cassol et al., 2012).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites Cassol et al., 2012 source
The paper relies on this without support.
The season of recording, classified by start date, accurately captures the relevant seasonal environmental exposure for each sleep study.
“For each study, the recording start date was used to classify the season as winter (December-February), spring (March-May), summer (June-August), or fall (September-November).”
The paper relies on this without support.
Data examining seasonal differences in both sleep structure and respiratory parameters using wearable-based home sleep studies remain limited.
“Despite this, data examining seasonal differences in both sleep structure and respiratory parameters using wearablebased home sleep studies remain limited.”
The paper relies on this without support.
Photoperiod (hours of daylight in Fresno, California) is a valid proxy for individual environmental light exposure relevant to sleep.
“In secondary analyses, photoperiod (hours of daylight in Fresno, California) was modeled as a continuous predictor to assess whether daylight duration was independently associated with sleep and respiratory outcomes after adjustment for age (and other covariates where specified).”
The paper relies on this without support.
Fresno, California has relatively mild photoperiod variation.
“The observation of seasonal variation in Fresno, California, a region with relatively mild photoperiod variation, is particularly notable.”
The paper relies on this without support.
The sample of adults referred for suspected sleep-disordered breathing is representative of adults undergoing home sleep assessment in Fresno, California.
“Each record represented one unique adult patient referred for diagnostic assessment in Fresno, California.”
Statistics recomputed
Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.
- ConsistentF(3, 2376) = 9.69reported p < .001 · recomputed p < .001
“F(3, 2376) = 9.69, p < .001”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Fall has the lowest obstructive AHI under the 4% criterion
MinorThe results describe obstructive AHI under both criteria as higher in winter and fall than in spring and summer. Table 1 instead reports fall as the lowest season for obstructive AHI under the 4% criterion (11.30).
“Similar patterns were observed for AHI (3%), obstructive AHI (3% and 4%), and respiratory disturbance indices, with higher values in winter and fall and lower values in spring and summer (Table 1).”
“Obstructive AHI (4%) 14.06 ± 15.60 12.86 ± 13.03 11.85 ± 12.50 11.30 ± 13.75 0.0087 0.060”
Fall is not the lowest season for the 3% apnea-hypopnea index
MinorThe abstract says apnea-hypopnea indices were lowest in fall, but Table 1 reports a lower 3% index in summer (19.60) than in fall (21.79).
“Apnea hypopnea indices were highest in winter and lowest in fall (p = 0.027)”
“Apnea-hypopnea index (3%) 22.77 ± 19.74 20.80 ± 17.98 19.60 ± 16.48 21.79 ± 18.31 0.0393 0.144”
Cites
Sleep physiology, pathophysiology, and sleep hygiene
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Circadian Entrainment to the Natural Light-Dark Cycle across Seasons and the Weekend
Stothard, E. R., McHill, A. W., Depner, C. M., Birks, B. R., Moehlman, T. M., Ritchie, H. K., Guzzetti, J. R., Chinoy, E. D., LeBourgeois, M. K., Axelsson, J., et al. (2017) · Current Biology · doi:10.1016/j.cub.2016.12.041 · Cited by 303 · see citing works
Seasonal variation in the human circadian rhythm: dissociation between sleep and temperature rhythm
Honma, K., Honma, S., Kohsaka, M., & Fukuda, N. (1992) · American Journal of Physiology-Regulatory, Integrative and Comparative Physiology · doi:10.1152/ajpregu.1992.262.5.r885 · Cited by 149 · see citing works
Is Sleep Apnea a Winter Disease?
Cassol, C. M., Martinez, D., da Silva, F. A. B. S., Fischer, M. K., Lenz, M. D. C. S., & Bós, Â. J. G. (2012) · Chest · doi:10.1378/chest.11-0493 · Cited by 89 · see citing works
Swaab, D. F., Van Someren, E. J. W., Zhou, J. N., & Hofman, M. A. (1996) · Progress in Brain Research · doi:10.1016/s0079-6123(08)60418-5 · Cited by 75 · see citing works
Seasonal Change in 24-Hour Blood Pressure and Heart Rate Is Greater Among Smokers Than Nonsmokers
Kristal-Boneh, E., Harari, G., & Green, M. S. (1997) · Hypertension · doi:10.1161/01.hyp.30.3.436 · Cited by 65 · see citing works
Summer-Winter Differences in 24 h Variability of Heart Rate
Kristal-Boneh, E., Froom, P., Harari, G., Malik, M., & Ribak, J. (2000) · European Journal of Cardiovascular Risk · doi:10.1177/204748730000700209 · Cited by 64 · see citing works
Evening daylight may cause adolescents to sleep less in spring than in winter
Figueiro, M. G., & Rea, M. S. (2010) · Chronobiology International · doi:10.3109/07420528.2010.487965 · Cited by 52 · see citing works
Seasonality of human sleep: Polysomnographic data of a neuropsychiatric sleep clinic
Seidler, A., Weihrich, K. S., Bes, F., de Zeeuw, J., & Kunz, D. (2023) · Frontiers in Neuroscience · doi:10.3389/fnins.2023.1105233 · Cited by 43 · see citing works
Air Pollutants Are Associated With Obstructive Sleep Apnea Severity in Non-Rapid Eye Movement Sleep
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Circadian rhythms and sleep-related breathing disorders
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Seasonal variability of sleep‐disordered breathing in children
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Circadian and circannual timescales interact to generate seasonal changes in immune function
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Seasonal variability in paediatric obstructive sleep apnoea
Walter, L. M., Nisbet, L. C., Nixon, G. M., Davey, M. J., Anderson, V., Trinder, J., Walker, A. M., & Horne, R. S. C. (2013) · Archives of Disease in Childhood · doi:10.1136/archdischild-2012-302599 · Cited by 17 · see citing works
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Seasonal Changes in Sleep Patterns in Two Saskatchewan First Nation Communities
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Flagged first, then by citations
- Authors
- Vazquez, I. M., Palomino, M., & DelRosso, L. M.
- Affiliations
- University of California, San Francisco (US)
- Inspire Health Medical Group Sleep Center, Fresno, California
- Corresponding author
- DelRosso, Lourdes M.
- ORCID
- DelRosso, Lourdes M.
- Venue
- Journal of Biological Rhythms
- Publisher
- SAGE Publications
- Published
- 2026-04-10
- Volume
- 41
- Issue
- 4
- Pages
- 487-496
- ISSN
- 0748-7304 (ISSN-L)
- 1552-4531
- OpenAlex
- W7153340467
- Semantic Scholar
- 8e592e466c8c058dc261a95627ce6c492eecbb83
- Cited by
- 0
- References
- 19
- FWCI
- 0.00
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Journal of Biological Rhythms (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Physiology › Obstructive Sleep Apnea Research
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
- Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
- Keywords
- seasonal variation, sleep patterns, home sleep apnea testing, wearable sleep monitoring, sleep latency, apnea-hypopnea index, oxygen desaturation, heart rate, seasonal temperature effects, age differences, sleep fragmentation, respiratory disturbance index
- MeSH terms
- Wearable Electronic Devices, Sleep Duration, Circadian Rhythm, Female, Heart Rate, Humans, Male, Respiration, Retrospective Studies, Seasons, Sleep, Polysomnography
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.
Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.
Cited sources are checked by gpt-6-sol.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
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